Ultrasonic probes have multiple transducers, each of which converts an electric signal fed from an ultrasonic diagnosis apparatus into ultrasonic waves and transmits the ultrasonic waves to a subject, or receives reflected echoes generated from the subject and converts the echoes into a received signal, set in array. As the transducer, what employs a vibrational element whose ultrasound transmitting/receiving sensitivity varies depending on an applied bias voltage is known.
Herein, by controlling the bias voltage to be applied to electrodes of the vibrational element, the ultrasound transmitting/receiving sensitivity can be controlled (refer to, for example, patent document 1).
Patent document 1: JP-A-2004-274756